セロトニンアナログ^<18>F-メチルトリプトファンを用いたうつ病発症機序の基礎的研究

F-18 α甲基色氨酸（^<18>FAMTP）是我所利用回旋加速器系统新合成的反映氨基酸代谢的F-18标记氨基酸之一。本研究的目的是用18F正电子核素合成α -甲基色氨酸，并利用该标记分子研究与血清素代谢相关的神经递质功能障碍的成像诊断的潜在效用。采用直接亲电氟化法合成^<18>FAMTP。在动物实验中，将含有370kBq ^<18>FAMTP的100ul体积注射到BALB/C雌性小鼠体内，在10分钟、30分钟和60分钟测量生物分布。通过每次解剖小鼠，心脏、肾脏和骨骼都可以看到高摄入量。早期在肾脏摄取意味着从肾脏中快速冲洗。骨的高摄取不像^<18>的FAMTP，这表明^<18>的FAMTP在体内是不稳定的，并导致高游离^<18>的F离子。一个特点是心脏的高摄取。这表明心肌正在进行血清代谢

F-18 alphamethyltryptophan (^<18>FAMTP) which is newly synthesized at our institute with use of Cyclotron system, is one of F-18 labeled amino acid reflecting the amino acid metabolism. The aim of this study was to synthesize the alpha-methyltryptophan with 18F positron nuclide and use this labeled molecule to investigate the potential utility of imaging diagnosis for neurotransmitter malfunction related with serotonin metabolism. Synthesis of ^<18>FAMTP was performed by direct electrophilic fluorination. In animal experiments, A volume of 100ul containing 370kBq of ^<18>FAMTP was injected into BALB/C female mice to measure bio-distribution at 10 minutes, 30 minutes and 60 minutes. By dissecting mice at each time, high uptakes were seen at heart, kidney and bone. Uptake at kidney at early time means rapid washout from kidney. High uptake in bone which is not like a ^<18>FAMT suggested that ^<18>FAMTP is unstable in vivo and resulted in high free ^<18>F ion. One characteristic is high uptake in heart. that suggest serotonic metabolism are taking place in heart muscle